[MPICH] MPI_Send() return condition

[Yipkei Kwok]

Hi,

Traditionally, MPI_Send() returns under one of the following conditions.

1. a matching receive call occurs
2. the message is copied into a system buffer (even if it still has not 
reached the receiver

I am running MPICH2 Release 1.0.6 on Linux PPC 64-bits. I know that the 
choice between the 2 options above is implementation-dependent. How can 
I force the run-time to pick a specific option without replacing 
MPI_Send() with MPI_Ssend() or MPI_Bsend()?

Thank you very much!

Regards,
Yipkei